Multiple torsion spring



Sept. 949. E s, PRENGLE ASLS? MULTIPLE ToRsoN SPRING Filed Feb. 25, 1946 2 sheets-sheet 1 INVENTOR DWH/F0 .5. PH//VGE BY 77M, ZM, 9%@ r 21W /J/s ATTORNEYS 6, W9. I E. s. PRINGLE 48h03? MULTIPLE TORS ION SPRING Filed Feb. 23, 1346 2 Sheets-Sheet 2 EMMA-l, gw, aww/afa T' Bm -WS ATTORNEYS Patented Sept. 6, 1949 MULTIPLE TORSIN SPRING Edward S, Pringle, Norfolk, Va., ,assigner to The J. G. Wilson Corporation, New York, N. Y a corporation of Virginia Application February 23, 1946, Serial No. 649,669

5 Claims.

lrThis invention relates to door operating apparatus and more particularly concerns an improved torsion spring and associated mechanism for use in operating a door.

vertically movable doors of the type used for residential garages and like building entrances may be conveniently operated by power mechanisln, One form of such mechanism that I have devised includes torsion spring which is charged or Wound up as the door is lowered and which unwinds and exerts a lifting )force on the door when the door is released from its lowered closed position. This spring is preferably housed in a rotary drum connected to the door by flexiible means such as cables, and an electric motor is providedto turn the drum in a direction to Wind up or .charge tbc spring and so to tbc door to close by gravity.

It is desirable that the torsion spring employed in the above described and like door operating mechanisms have sufficient strength to 'lift the door or to counterbalance its weight, and it is further desirable that the spring mechanism be relatively small and compact.

The present invention has for its object the provision of an .improved torsion spring mecha nisln useful for the above described 4and like purposes, which combines high strength with relatively small overall dimensions. A further ob icct of the invention .is tho provision of a spring and drum mech mism including the improved spring structure for use in operating a veically movable door or like closure. Other specific objects and advantages of invention will be- 4come apparent from the appended description of a typical embodiment thereof.

In describing thc invention in detail, reference will .be made to the accompanying drawing in which an embodiment of the invention is illus trated. 'In the drawings;

Fig. l is a sectional elevation of a torsion spring and associated mechanism embodying my invention;

Figs. 2 and 3 are respectively sectional views taken along the lines 2--2 and 3 3 of Fig. l and viewed in the direction of the arrows;

1Eig. 4 is a simplified perspective view oi a tor- Sion spring mechanism embodying the invention and connected to a vertically movable sectional door;

5 is a sectional elevation, similar to `Fig. l. Showing a modneol form of torsion spring and associated door operating mechanism embodyj ing my invention; and

Fig. 6 is a sectional view taken along the line 51.-.5 of Fig. 5 and viewed in the direction of the arrows.

Referring to the drawings, a sectional, verr tically movable door .5 of AKnown construction is illustrated in Fig. ll. .door is mounted and guided by rollers ii running in guide tracks l which extend vertically alone opposite sides of the door opening and curve back to extend Sub. stantially horizontally `along the ceiling of the building. The door moves from the closed poe sition shown upwardly and rearwardly along the tracks to its open position. Cables 8 are secured to the bottoni section of the door s and a disposed to be Wound on `a rotary' drum 9 to e. .l the cable ends may be suitably secured as by the set vscrews lll.

,Rfierring .to the drum S which is illustrated detail .in Figs. l., 2 and 3, it is fixed to a rotary tube l l.. 0.1.1.6 ond .of which is journalled on a post il: nxei to a wall bracket it. a bearing lo being disposed between .the post and the tube. The opposite end of the tube ll is fixed to the shaft .it of an electric `motor .I6 by an end plus H the motor is suitably secured to the ceiling or other fixed support .as illustrated in Fig. 4. With this arrangement, the motor bearing il" .serves as the outer journal bearing for rotatably supporting the tube Il and drum 9. A coiled torsion spring unit S is disposed within the tube ll.. In accordance with my invention, this sp-ring unit is made up of two elongated cylindrical helically coiled torsion springs iii and .IS which are telescopically nested together, the spring i8 being inside of the spring l2. The springs i8 and lil are of substantially equal length and are nearly coextensive with the tube ll, although in the disclosed embodiment the outer spring le terminates short of the lefthend endA of the tube il and of the inner spring i8. As shown in Figs.. 1 and 2, both of the springs E3 and laare wound in the same direction cir @lm ferentially thereof. that is, their succssive turns progressing from left to right as viewed in Fig. are Wound clockwise as viewed from 'tho .right end, as in Fig. 2, but Whereas the successive turns of the i. ner spring is Y.regress toward. the right. viewed in Fig. il. successive turns of the outer spring I9 progress in the opposite direction, that is, toward the le as viewed the Some neuro.

The first turn at the left end of the inner spring 8 is suitably secured to the fixed post l2 as by passing a diametrieally bent end 2G of the spring turn through a transverse opening in the post (See Fig. 3). The last turn at the left end of the outer spring I9 is suitably secured to the tube II and to the drum 9 as byl inserting an outwardly bent end 2| of the last turn into aligned openings 22 in the tube and the drum. These left ends of the two springs which are respectively connected to the flxcd post and to the rotary tube and drum structure may for convenience be referred to as the xed ends of the springs I8 and I 9. The last turn at the right or free end of the inner spring El 81 is directly secured to the rst turn at the right or free end of the outer spring I9 by any suit-i able means. In the disclosed embodiment, a block 23 receives the two spring ends in transverse openings therein, and set screws 24 hold the spring ends in the block openings.

With the described arrangement, the two springs I8 and I 9 are connected in series to form a single compact torsion spring unit which may .be charged or wound up by turning the tube Il clockwise as viewed in Figs. 2 `and 3. This spring winding rotation may be imparted to the tube I l .by operation of the motor 6, and in the disclosed embodiment this rotation results in a lowering of the door I5 by gravity since during such rotation the cables 8 are payed out from the drum S. When it is desired to raise the door 5, a suitable latch mechanism on the door may be released, whereupon :the spring unit S exerts a torsional force which acts to turn the tube II Iand drum 9 and so wind the cables 8 on the drum and raise the door.

The described arrangement incorporates a multiple spring unit wherein one spring is connected at one end to a fixed support and at the other end directly to one the other end of which is attached to the rotary drum. This construction permits the two springs to be nested together telescopically within the drum tube .to produce a spring unit of small dimensions and large power output.

In the modified form of my invention illustrated in Figs. 5 and 6, the tubular member which encloses the torsion spring unit S' comprises a relatively short cable drum portion 25 of reduced diameter secured co-axially to one end of a relatively long portion 26 of larger diameter. 'Ilhe door lifting cables 8 are secured to the cable drum .portion 25 by suitable means such as the set screws IG. The inner coiled torsion spring I 8 is longer th-an the outer spring I 9. As shown, the right hand ends of the two springs I8 and I9 which are interconnected by the Iblock 23 are substantially aligned, whereas the left hand end of the outer spring I9 terminates short of the left hand end of the inner spring I8 by `an interval substantially equal to the length of the reduced diameter drum portion 25 of the tubular spring housing member. The difference in length between the springs I8 and I9 is preferably small in proportion to their total lengths, and may comprise a few inches as compared to a total spring length of several feet. The reduced drum portion 25 is just large enough to enclose the relatively small diameter inner spring i8', and the larger diameter tubular portion 25 is of suiiicient diameter to enclose the outer spring I9.

The two portions 25 and 2B of the tubular member may be connected by any suitable means, and as shown, a sleeve or ring 21 is employed for this purpose. The outer surface of the sleeve 2l engages the inner wall of the left end of the tubular portion 26, and the inner surface of the sleeve engages the outer Wall of the tubular drum end of the other spring,

portion 25. The sleeve 21 may be secured to the respective tubular portions 26 and 21 by a press fit, by welding or in any other suitable manner. The sleeve 2'I is preferably split as shown in Fig. 6 to provide an opening 28 into which an aXial extension 29 at the left end of the outer spring I9 is inserted. This forms a driving connection ybetween the left end of the outer spring I9 and the tubular member.

The parts of the modification of Figs. 5 and 6 not specifically described are substantially identical with the corresponding parts of the modiiication of Figs. 1 to 4, Iand are designated by like reference characters bearing distinctive ex ponents.

The modification of Figs. 5 and 6 operates in the same manner as has been described above in connection with the previously described embodiment. The stepped diameter of the tubular member enclosing the spring unit in combination with the arrangement of the outer spring terminating short of the reduced cable drum `por-tion permits the use oi Ian outer spring of relatively large diameter while employing a small diameter cable drum with a resultant reduction in the torque load on the torsion spring.

A particular advantage of lthe disclosed multiple torsion-al spring structures is that they permit the use of a relatively small diameter cable drum with a resultant reduction in the torque load on the spring, while at the same time keeping the spring relatively short. A small cable drum -diameter is desirable in that by reducing the torque load, it permits the use of a smaller wire size in the spring. At the same time, however, the small cable drum diameter makes necessary a greater number of turns of the drum in moving the door a given distance, and hence a greater number of turns of the torsional spring which rotates the drum. With the improved construction of the invention, a large number of spring turns is provided in a relatively short structure whereby the advantages of a small cable drum can be achieved in a spring structure of moderate length. By employing the described stepped construction of the tubular member, a further reduction in the torque load on the spring is obtained.

I claim:

1. In a spring operated device, in combination, a rotary tubular member, a fixed post extending into one end of said tubular member, a bearing connecting one end of said tubular member to said post, an electric motor directly connected to the other end of said tubular member to rotate the l same, an inner helically coiled torsion spring within and substantially coextensive with said tubular member and having a xed end secured to said post and a free end adjacent the opposite end of said tubular member, and an outer helically coiled torsion spring in said tubular member surrounding and substantially coextensive with said inner spring `and having 4a free end directly connected with the free end of said inner spring independently of said tubular member and a fixed end secured to said tubular member adjacent the xed end of said inner spring, the successive turns of said springs being wound in the same direction circumferentially thereof but progressing in opposite directions longitudinally thereof.

2. In a spring operated device, in combination, a fixed member, a tubular member rotatably supported adjacent said fixed member and having a drum portion of reduced diameter adjacent one r end thereof, a pair of helically coiled elongated torsion springs nested telescopically one within the other and disposed within said tubular member, the inner of said nested springs extending substantially throughout the length of said tubular member and the outer of said nested springs terminating short of said end portion of reduced diameter, means for connecting the end of said inner spring within said tubular end portion oi reduced diameter to said fixed member, means for connecting the adjacent end of said outer spring to said tubular member and means for connecting the other ends of said springs together independently of said tubular member.

3. In a spring operated device, in combination with a xed support and an elongated tubular member having a cable drum portion of reduced diameter at one end thereof and rotatably connected at said end to said support, an inner helically coiled torsion spring within and substantially co-extensive with the entire length of said tubular member, means ior connecting one end of said inner spring to said fixed support, an outer helically coiled torsion spring surrounding said inner spring, said outer spring being of a diameter larger than the inner diameter of said cable drum portion and terminating adjacent the inner end of said cable drum portion, means for connecting the end of said outer spring that is adjacent said cable drum portion to said tubular member and means for interconnecting the ends of said inner and outer springs that are remote from said cable drum portion.

4. In a spring operated device, in combination with a xed support and an elongated tubular member having a tubular cable drum portion of reduced diameter at one end thereof, means for rotatably connecting the cable drum end of said tubular member to said Xed support, an inner helically coiled torsion spring within said tubular member and extending substantially from end to end thereof and having a fixed end within said cable drum portion connected to said Xed support and a free end adjacent the opposite end of said tubular member, an outer helically coiled torsion spring within said tubular member surrounding said inner spring and extending from the inner end of said reduced cable drum portion substantially to the free end of said inner spring, means for connecting the end of said outer spring that is adjacent said cable drum portion to said tubular member and means for connecting the other end of said outer spring to the free end of said inner spring independently of said tubular member.

5. In a spring operated device, in combination, a rotary hollow tubular member comprising a body portion and a `co-axial drum end portion of smaller diameter than said body portion having its inner end extending within the end of said body portion, a sleeve surrounding and secured to said inner end of said drum end portion and engaging and secured to the inner surface of the surrounding end of said body portion, a xed post extending into the outer end of said drum end portion, means for rotatably connecting said drum end portion to said post, an inner helically coiled torsion spring within and co-extensive with said connected portions of said tubular member and having a xed end secured to said post and a free end adjacent the opposite end of said tubular member, said inner spring having an outer diameter less than the inner diameter of said drum end portion, and an outer helically coiled torsion spring Within the body por-tion of said tubular member surrounding said inner spring in said body portion and having a free end remote from said drum end portion and directly connected to the free end of said inner spring independently of said tubular member and a fixed end adjacent the inner end of said drum end portion and secured to said sleeve.

EDWARD S. PRINGLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 633,328 Roberts Sept. 19, 1899 r[40,114 Fiske Sept. 29, 1903 1,464,294 Ruse Aug. 7, 1923 1,723,484 Krepps Aug. 6, 1929 2,226,017 Pixley Dec. 24, 1940 FOREIGN PATENTS Number Country Date 85,808 Austria Oct. 10, 1921 

